# ------------------------------------------------------------------------------
# OCCAM
#
# Copyright (c) 2011-2012, SRI International
#
#  All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice, this
#   list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright notice,
#   this list of conditions and the following disclaimer in the documentation
#   and/or other materials provided with the distribution.
#
# * Neither the name of SRI International nor the names of its contributors may
#   be used to endorse or promote products derived from this software without
#   specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
# ------------------------------------------------------------------------------

class VersionedFile:
    def __init__(self, base, suffix, digits=2):
        self._base = base
        self._suffix = suffix
        self._version = 0
        self._format = "%s.%%0%dd.%s" % (base, digits, suffix)
    def new(self):
        self._version += 1
        return self.get()
    def get(self):
        if self._version == 0:
            return "%s.%s" % (self._base, self._suffix)
        else:
            return self._format % self._version   

class FileStream:
    def __init__(self, base, suffix):
        self._base = base
        self._suffix = suffix
        self._versions = []

    def new(self, ver=''):
        self._versions += [ver]
        return self.get()

    def get(self):
        return self._base + '.' + '.'.join(self._versions + [self._suffix])

    def base(self, mod=None):
        if mod is None:
            return self._base + '.' + self._suffix
        else:
            return self._base + mod + '.' + self._suffix

    def __len__(self):
        return len(self._versions)
